Body & brain: Brain takes note when others err: Some neurons light up only upon seeing a peer's...
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IN THE NEWS DANIEL STREICKER 12 | SCIENCE NEWS | September 8, 2012 www.sciencenews.org Brain takes note when others err Some neurons light up only upon seeing a peer’s mistake Rabies resistance arises Some people living in a vampire bat–ridden part of the Peru- vian Amazon seem to have developed natural resistance to the rabies virus. The discovery of antirabies antibodies in the blood of 14 percent of healthy individuals tested in two com- munities suggests that people had been exposed to the virus and survived, researchers from the U.S. Centers for Disease Control and Prevention and the Peruvian Ministry of Health write in the August American Journal of Tropical Medicine and Hygiene. Those testing positive for antibodies reported bites, scratches or skin contact from a vampire bat (shown). Only one person sampled reported having been vaccinated against rabies. “Why these individuals don’t die is very intriguing,” says disease ecologist Amy Gilbert of the CDC. Many factors may determine whether a bite leads to full-blown infection. The vampire bat’s relatively gentle bite may deliver a lower viral dose than a dog’s or raccoon’s. The proximity of the bite to the victim’s head can also play a role. Even the victim’s genetics may be important. — Rachel Ehrenberg By Laura Sanders When one monkey sees another mon- key messing up, the event ignites a small cluster of nerve cells in the brain that are sensitively tuned to others’ failures. The results may help explain why mem- bers of another primate species are such exquisite connoisseurs of blame. “We humans are very sensitive to oth- ers’ mistakes,” says Masaki Isoda of the Okinawa Institute of Science and Tech- nology in Japan. He and his colleagues describe macaques’ blunder detectors online August 5 in Nature Neuroscience. Catching other people’s slipups isn’t just schadenfreude. Noting anoth- er’s lapse, be it a gymnast’s step out of bounds or another animal’s regurgita- tion of a poisonous berry, is a good way to learn about the world. “Everybody’s life is a bit of a trial-and-error game,” says neuroscientist Matthew Shane of the Mind Research Network in Albu- querque, who was not involved in the new study. An ability to sense others’ errors helps people see what doesn’t work without suffering the conse- quences firsthand. Past studies have suggested that cer- tain nerve cells in a brain region called the medial frontal cortex are general error catchers: The cells were thought to fire when a person makes a mistake and also when wit- nessing someone else err. But by listening in on sin- gle nerve cells in macaques, Isoda and his team found that some of these neurons don’t seem to care about a personal mis- take. Instead, these neurons are exclu- sively trained on other animals’ errors. Isoda and colleagues taught macaque monkeys to press either a yellow or a green button for a liquid reward. After every two rounds, the two monkeys switched between pushing the button and watching. If the button pusher got the right answer, both monkeys got a treat. But if the answer was wrong, both monkeys were denied. Electrodes monitoring neuron behav- ior during the game found a small group of cells that fired away when a monkey watched its partner commit a treat- costing error, but not when the monkey itself messed up. (The researchers knew the observing monkey caught the error because it would not lick its lips in antici- pation of a reward.) People so readily pin the blame on a sister, neighbor or boss when things go wrong that it would make sense for people to also have nerve cells that can make these distinctions, Shane says. Creating a full sense of another person’s error involves other brain systems as well, says neuroscien- tist Ellen de Bruijn of Leiden University in the Netherlands. “You start to think about this other person and take the perspective of this other person,” she says. That kind of sophisticated social reasoning probably involves brain areas outside the medial frontal cortex, she says. s “Everybody’s life is a bit of a trial-and- error game.” MATTHEW SHANE Body & Brain For longer versions of these and other Body & Brain stories, visit www.sciencenews.org
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Transcript of Body & brain: Brain takes note when others err: Some neurons light up only upon seeing a peer's...
in the news
Dan
iel
Str
eic
ker
12 | science news | September 8, 2012 www.sciencenews.org
Brain takes note when others errSome neurons light up only upon seeing a peer’s mistake
Rabies resistance arisesSome people living in a vampire bat–ridden part of the Peru-vian amazon seem to have developed natural resistance to the rabies virus. the discovery of antirabies antibodies in the blood of 14 percent of healthy individuals tested in two com-munities suggests that people had been exposed to the virus and survived, researchers from the U.S. centers for Disease control and Prevention and the Peruvian Ministry of Health write in the august American Journal of Tropical Medicine and Hygiene. those testing positive for antibodies reported bites, scratches or skin contact from a vampire bat (shown). Only one person sampled reported having been vaccinated against rabies. “Why these individuals don’t die is very intriguing,” says disease ecologist amy Gilbert of the cDc. Many factors may determine whether a bite leads to full-blown infection. the vampire bat’s relatively gentle bite may deliver a lower viral dose than a dog’s or raccoon’s. the proximity of the bite to the victim’s head can also play a role. even the victim’s genetics may be important. — Rachel Ehrenberg
By Laura Sanders
When one monkey sees another mon-key messing up, the event ignites a small cluster of nerve cells in the brain that are sensitively tuned to others’ failures. The results may help explain why mem-bers of another primate species are such exquisite connoisseurs of blame.
“We humans are very sensitive to oth-ers’ mistakes,” says Masaki Isoda of the Okinawa Institute of Science and Tech-nology in Japan. He and his colleagues describe macaques’ blunder detectors online August 5 in Nature Neuroscience.
Catching other people’s slipups isn’t just schadenfreude. Noting anoth-er’s lapse, be it a gymnast’s step out of bounds or another animal’s regurgita-tion of a poisonous berry, is a good way to learn about the world. “Everybody’s life is a bit of a trial-and-error game,” says neuroscientist Matthew Shane of the Mind Research Network in Albu-querque, who was not involved in the
new study. An ability to sense others’ errors helps people see what doesn’t work without suffering the conse-quences firsthand.
Past studies have suggested that cer-tain nerve cells in a brain region called the medial frontal cortex are general error catchers: The cells were thought to fire when a person makes a mistake and also when wit-nessing someone else err. But by listening in on sin-gle nerve cells in macaques, Isoda and his team found that some of these neurons don’t seem to care about a personal mis-take. Instead, these neurons are exclu-sively trained on other animals’ errors.
Isoda and colleagues taught macaque monkeys to press either a yellow or a green button for a liquid reward. After every two rounds, the two monkeys switched between pushing the button and watching. If the button pusher got the right answer, both monkeys got a
treat. But if the answer was wrong, both monkeys were denied.
Electrodes monitoring neuron behav-ior during the game found a small group of cells that fired away when a monkey watched its partner commit a treat-costing error, but not when the monkey itself messed up. (The researchers knew the observing monkey caught the error because it would not lick its lips in antici-pation of a reward.)
People so readily pin the blame on a sister, neighbor or boss when things go wrong that it would make sense for people to also have nerve cells that can make these distinctions, Shane says.
Creating a full sense of another person’s error involves other brain systems as well, says neuroscien-tist Ellen de Bruijn of Leiden University in the Netherlands. “You start to think about this other person and take the perspective of this other person,” she says. That kind of sophisticated social reasoning probably involves brain areas outside the medial frontal cortex, she says. s
“Everybody’s life is a bit of a trial-and-
error game.”Matthew Shane
Body & Brain For longer versions of these and other Body & Brain stories, visit www.sciencenews.org
body&brain.indd 12 8/22/12 11:32 AM
